1. Field of the Invention
The present invention relates to a pneumatic tire having an improved icy road performance while maintaining steering stability on dry roads.
2. Description of the Related Art
Recent years, in order to improve icy road performance of tires, Japanese unexamined Patent Application Publication No. 2010-274695 discloses a pneumatic tire having a tread block provided with a plurality of sipes that divide it into a plurality of block-pieces with edges for scratching an icy road surface. Typically, adjacent block-pieces divided by the sipe are usually easy to deform or slide each other through the sipe surfaces when the tire is subjected to friction force on the road, such that each edge of the block-pieces provides high friction force by scratching the icy road surface.
However, the large deformation of block-pieces causes loss of ground contact area of the tread block, whereby steering stability of the tire on dry roads tends to deteriorate.